The avoid occupants behavior maintains a “comfort zone” between the occupant and other surrounding simulation occupants. This behavior first creates a list of occupants within a frustum whose size is controlled by the velocity of the occupant. Then the behavior projects a moving sphere ahead of the occupant in the direction of the projected point. This sphere is tested against another moving sphere for each nearby occupant. If none of the moving spheres collide the cost is zero, otherwise the cost is based on how far the occupant can travel prior to the collision. The closer this collision point, the higher the cost of the steering behavior